/*
    ChibiOS - Copyright (C) 2006..2015 Giovanni Di Sirio

    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
    You may obtain a copy of the License at

        http://www.apache.org/licenses/LICENSE-2.0

    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
*/

/**
 * @file    uart.c
 * @brief   UART Driver code.
 *
 * @addtogroup UART
 * @{
 */

#include "hal.h"

#if (HAL_USE_UART == TRUE) || defined(__DOXYGEN__)

/*===========================================================================*/
/* Driver local definitions.                                                 */
/*===========================================================================*/

/*===========================================================================*/
/* Driver exported variables.                                                */
/*===========================================================================*/

/*===========================================================================*/
/* Driver local variables and types.                                         */
/*===========================================================================*/

/*===========================================================================*/
/* Driver local functions.                                                   */
/*===========================================================================*/

/*===========================================================================*/
/* Driver exported functions.                                                */
/*===========================================================================*/

/**
 * @brief   UART Driver initialization.
 * @note    This function is implicitly invoked by @p halInit(), there is
 *          no need to explicitly initialize the driver.
 *
 * @init
 */
void uartInit(void) {

  uart_lld_init();
}

/**
 * @brief   Initializes the standard part of a @p UARTDriver structure.
 *
 * @param[out] uartp    pointer to the @p UARTDriver object
 *
 * @init
 */
void uartObjectInit(UARTDriver *uartp) {

  uartp->state   = UART_STOP;
  uartp->txstate = UART_TX_IDLE;
  uartp->rxstate = UART_RX_IDLE;
  uartp->config  = NULL;
  /* Optional, user-defined initializer.*/
#if defined(UART_DRIVER_EXT_INIT_HOOK)
  UART_DRIVER_EXT_INIT_HOOK(uartp);
#endif
}

/**
 * @brief   Configures and activates the UART peripheral.
 *
 * @param[in] uartp     pointer to the @p UARTDriver object
 * @param[in] config    pointer to the @p UARTConfig object
 *
 * @api
 */
void uartStart(UARTDriver *uartp, const UARTConfig *config) {

  osalDbgCheck((uartp != NULL) && (config != NULL));

  osalSysLock();
  osalDbgAssert((uartp->state == UART_STOP) || (uartp->state == UART_READY),
                "invalid state");

  uartp->config = config;
  uart_lld_start(uartp);
  uartp->state = UART_READY;
  osalSysUnlock();
}

/**
 * @brief   Deactivates the UART peripheral.
 *
 * @param[in] uartp     pointer to the @p UARTDriver object
 *
 * @api
 */
void uartStop(UARTDriver *uartp) {

  osalDbgCheck(uartp != NULL);

  osalSysLock();
  osalDbgAssert((uartp->state == UART_STOP) || (uartp->state == UART_READY),
                "invalid state");

  uart_lld_stop(uartp);
  uartp->state = UART_STOP;
  uartp->txstate = UART_TX_IDLE;
  uartp->rxstate = UART_RX_IDLE;
  osalSysUnlock();
}

/**
 * @brief   Starts a transmission on the UART peripheral.
 * @note    The buffers are organized as uint8_t arrays for data sizes below
 *          or equal to 8 bits else it is organized as uint16_t arrays.
 *
 * @param[in] uartp     pointer to the @p UARTDriver object
 * @param[in] n         number of data frames to send
 * @param[in] txbuf     the pointer to the transmit buffer
 *
 * @api
 */
void uartStartSend(UARTDriver *uartp, size_t n, const void *txbuf) {

  osalDbgCheck((uartp != NULL) && (n > 0U) && (txbuf != NULL));
             
  osalSysLock();
  osalDbgAssert(uartp->state == UART_READY, "is active");
  osalDbgAssert(uartp->txstate != UART_TX_ACTIVE, "tx active");

  uart_lld_start_send(uartp, n, txbuf);
  uartp->txstate = UART_TX_ACTIVE;
  osalSysUnlock();
}

/**
 * @brief   Starts a transmission on the UART peripheral.
 * @note    The buffers are organized as uint8_t arrays for data sizes below
 *          or equal to 8 bits else it is organized as uint16_t arrays.
 * @note    This function has to be invoked from a lock zone.
 *
 * @param[in] uartp     pointer to the @p UARTDriver object
 * @param[in] n         number of data frames to send
 * @param[in] txbuf     the pointer to the transmit buffer
 *
 * @iclass
 */
void uartStartSendI(UARTDriver *uartp, size_t n, const void *txbuf) {

  osalDbgCheckClassI();
  osalDbgCheck((uartp != NULL) && (n > 0U) && (txbuf != NULL));
  osalDbgAssert(uartp->state == UART_READY, "is active");
  osalDbgAssert(uartp->txstate != UART_TX_ACTIVE, "tx active");

  uart_lld_start_send(uartp, n, txbuf);
  uartp->txstate = UART_TX_ACTIVE;
}

/**
 * @brief   Stops any ongoing transmission.
 * @note    Stopping a transmission also suppresses the transmission callbacks.
 *
 * @param[in] uartp     pointer to the @p UARTDriver object
 *
 * @return              The number of data frames not transmitted by the
 *                      stopped transmit operation.
 * @retval 0            There was no transmit operation in progress.
 *
 * @api
 */
size_t uartStopSend(UARTDriver *uartp) {
  size_t n;

  osalDbgCheck(uartp != NULL);

  osalSysLock();
  osalDbgAssert(uartp->state == UART_READY, "not active");

  if (uartp->txstate == UART_TX_ACTIVE) {
    n = uart_lld_stop_send(uartp);
    uartp->txstate = UART_TX_IDLE;
  }
  else {
    n = 0;
  }
  osalSysUnlock();

  return n;
}

/**
 * @brief   Stops any ongoing transmission.
 * @note    Stopping a transmission also suppresses the transmission callbacks.
 * @note    This function has to be invoked from a lock zone.
 *
 * @param[in] uartp     pointer to the @p UARTDriver object
 *
 * @return              The number of data frames not transmitted by the
 *                      stopped transmit operation.
 * @retval 0            There was no transmit operation in progress.
 *
 * @iclass
 */
size_t uartStopSendI(UARTDriver *uartp) {

  osalDbgCheckClassI();
  osalDbgCheck(uartp != NULL);
  osalDbgAssert(uartp->state == UART_READY, "not active");

  if (uartp->txstate == UART_TX_ACTIVE) {
    size_t n = uart_lld_stop_send(uartp);
    uartp->txstate = UART_TX_IDLE;
    return n;
  }
  return 0;
}

/**
 * @brief   Starts a receive operation on the UART peripheral.
 * @note    The buffers are organized as uint8_t arrays for data sizes below
 *          or equal to 8 bits else it is organized as uint16_t arrays.
 *
 * @param[in] uartp     pointer to the @p UARTDriver object
 * @param[in] n         number of data frames to send
 * @param[in] rxbuf     the pointer to the receive buffer
 *
 * @api
 */
void uartStartReceive(UARTDriver *uartp, size_t n, void *rxbuf) {

  osalDbgCheck((uartp != NULL) && (n > 0U) && (rxbuf != NULL));

  osalSysLock();
  osalDbgAssert(uartp->state == UART_READY, "is active");
  osalDbgAssert(uartp->rxstate != UART_RX_ACTIVE, "rx active");

  uart_lld_start_receive(uartp, n, rxbuf);
  uartp->rxstate = UART_RX_ACTIVE;
  osalSysUnlock();
}

/**
 * @brief   Starts a receive operation on the UART peripheral.
 * @note    The buffers are organized as uint8_t arrays for data sizes below
 *          or equal to 8 bits else it is organized as uint16_t arrays.
 * @note    This function has to be invoked from a lock zone.
 *
 * @param[in] uartp     pointer to the @p UARTDriver object
 * @param[in] n         number of data frames to send
 * @param[out] rxbuf    the pointer to the receive buffer
 *
 * @iclass
 */
void uartStartReceiveI(UARTDriver *uartp, size_t n, void *rxbuf) {

  osalDbgCheckClassI();
  osalDbgCheck((uartp != NULL) && (n > 0U) && (rxbuf != NULL));
  osalDbgAssert(uartp->state == UART_READY, "is active");
  osalDbgAssert(uartp->rxstate != UART_RX_ACTIVE, "rx active");

  uart_lld_start_receive(uartp, n, rxbuf);
  uartp->rxstate = UART_RX_ACTIVE;
}

/**
 * @brief   Stops any ongoing receive operation.
 * @note    Stopping a receive operation also suppresses the receive callbacks.
 *
 * @param[in] uartp     pointer to the @p UARTDriver object
 *
 * @return              The number of data frames not received by the
 *                      stopped receive operation.
 * @retval 0            There was no receive operation in progress.
 *
 * @api
 */
size_t uartStopReceive(UARTDriver *uartp) {
  size_t n;

  osalDbgCheck(uartp != NULL);

  osalSysLock();
  osalDbgAssert(uartp->state == UART_READY, "not active");

  if (uartp->rxstate == UART_RX_ACTIVE) {
    n = uart_lld_stop_receive(uartp);
    uartp->rxstate = UART_RX_IDLE;
  }
  else {
    n = 0;
  }
  osalSysUnlock();

  return n;
}

/**
 * @brief   Stops any ongoing receive operation.
 * @note    Stopping a receive operation also suppresses the receive callbacks.
 * @note    This function has to be invoked from a lock zone.
 *
 * @param[in] uartp      pointer to the @p UARTDriver object
 *
 * @return              The number of data frames not received by the
 *                      stopped receive operation.
 * @retval 0            There was no receive operation in progress.
 *
 * @iclass
 */
size_t uartStopReceiveI(UARTDriver *uartp) {

  osalDbgCheckClassI();
  osalDbgCheck(uartp != NULL);
  osalDbgAssert(uartp->state == UART_READY, "not active");

  if (uartp->rxstate == UART_RX_ACTIVE) {
    size_t n = uart_lld_stop_receive(uartp);
    uartp->rxstate = UART_RX_IDLE;
    return n;
  }
  return 0;
}

#endif /* HAL_USE_UART == TRUE */

/** @} */
